{"title":"Microwave-activated Synthetic Route to Various Biologically Important Heterocycles Involving Transition Metal Catalysts","authors":"Soumyadip Basu, C. Mukhopadhyay","doi":"10.2174/0122133356267427231120062925","DOIUrl":"https://doi.org/10.2174/0122133356267427231120062925","url":null,"abstract":"\u0000\u0000This study incorporates the assembly of development methodologies of microwave-acti-vated protocol involving transition metal catalysts for the synthesis of numerous biologically im-portant heterocycles during the past few years. Herein, it highlights the potential of transition metal salts as catalysts in multicomponent reactions performed under microwave conditions for the for-mation of oxygen, nitrogen, and sulphur-containing bioactive heterocycle moieties. Microwave-activated organic synthesis has been well-utilized as an alternative to conventional methodology in pharmaceutical companies due to its potential to significantly improve the rate and consequently diminish the time span of the synthetic process. The traditional methods involving transition metal catalysts for synthesizing bioactive heterocyclic molecules are prolonged and, thus, difficult to meet the requirements for the timely supply of these important compounds. In our review, our main focus is on integrating such synthetic strategies involving transition metal catalysis with a microwave-activated multicomponent approach for developing bioactive heterocycles.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":"108 ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139011233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Omar Merino Pérez, Ricardo Cerón-Camacho, Rafael Martinez Palou
{"title":"One-step Synthesis of Deep Eutectic Solvents and dissolution of their Kraft Lignin","authors":"Omar Merino Pérez, Ricardo Cerón-Camacho, Rafael Martinez Palou","doi":"10.2174/0122133356264245231120053530","DOIUrl":"https://doi.org/10.2174/0122133356264245231120053530","url":null,"abstract":"\u0000\u0000Lignin is a very abundant biopolymer with great potential to produce other high-value polymers with aromatic groups. Its valorization has been limited principally by its poor solubility in conventional organic solvents, which makes it difficult to deconstruct or transform it into other products with higher added value. In this work, we describe a one-pot procedure to prepare vari-ous Deep Eutectic Solvents and study their ability to dissolve Kraft lignin with the aid of micro-wave dielectric heating efficiently.\u0000\u0000\u0000\u0000Lignin is a widely available aromatic biopolymer that is largely discarded or used as a low-value fuel when separated in paper production processes, so researchers are engaged in the development of lignin dissolution processes that allow its easy deconstruction and transfor-mation into other products with higher added value.\u0000\u0000\u0000\u0000The main objective of this work is to find deep eutectic solvents capable of dissolving significant quantities of lignin with the aid of microwaves as a heating source.\u0000\u0000\u0000\u0000The present work developed a simple, fast, and efficient method to dissolve lignin using Deep Eutectic Solvent/acetonitrile as solvents and irradiation by dielectric microwave heating.\u0000\u0000\u0000\u0000Most of the DESs studied achieved significant dissolution of purchased lignin with com-mon organic solvents by employing microwave irradiation as the heating method.\u0000\u0000\u0000\u0000Some DESs studied in this work are good alternatives as solvents for lignin due to the solvent option of simple preparation from renewable precursors from biomass, such as glyc-erol, choline chloride, and urea, of low toxicity and cost for this application. The effectiveness of these systems appears to be based on molecular recognition by hydrogen bonding interactions involving the three species that make up the eutectic and the hydroxyl groups of the lignin. These solvents can be recovered and recycled.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":"88 3","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139011575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pranali Hadole, Sampat R. Shingda, Aniruddha Mondal, Kundan Lal, R. Chaudhary, Sudip Mondal
{"title":"Infusion of Magnetic Nanocatalyst to Microwave Propped Synthesis of\u0000Bioactive Azaheterocycles","authors":"Pranali Hadole, Sampat R. Shingda, Aniruddha Mondal, Kundan Lal, R. Chaudhary, Sudip Mondal","doi":"10.2174/0122133356269940231116134734","DOIUrl":"https://doi.org/10.2174/0122133356269940231116134734","url":null,"abstract":"\u0000\u0000Microwave-assisted synthesis is a powerful tool in organic chemistry, providing a\u0000rapid and efficient method for the synthesis of bioactive heterocycles. The application of microwaves significantly reduces reaction times and increases percentage yields with high purity of the\u0000final product. To make the synthetic protocol greener, the application of the magnetic nanocatalyst is a rapidly growing area of interest nowadays. Magnetic nanocatalyst, with its unique features like magnetic separable facile recovery from the reaction media heterogeneously, makes the\u0000overall synthetic strategy cleaner, faster, and cost-effective. Aiming this, in the present review,\u0000we will focus on the infusion of Magnetic nanocatalyst to microwave-assisted synthesis of various classes of azaheterocyclic compounds, including pyridines, pyrimidines, quinolines, and benzimidazoles. The synthetic methodologies involved in the preparation of these heterocycles are\u0000highlighted, along with their biological activities. Furthermore, in this review, the most recent\u0000and advanced strategies to incorporate nanocatalysts in the microwave-assisted synthesis of natural products containing azaheterocyclic moieties in drug discovery programs are elucidated in\u0000detail, along with the incoming future scope and challenges\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":"19 10","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138601970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}